Global communications networks witness a tendency towards network construction centered on a data center. There is a big change in a network traffic model in the era of cloud computing, with 16 percent (%) of traffic on operator networks, 14% of the traffic on enterprise networks, and the remaining 70% of the traffic all flowing to insides of data centers. An exponential growth in data center traffic and bandwidth has been far beyond people's expectations on a traditional network. Large bandwidth and a high extensibility capability have become the chief demands of data center customers. A bottleneck of data center network construction is also increasingly obvious.
FIG. 1 is a schematic diagram of a network structure of an existing large-scale data center. In this data center, all servers can be connected for interworking only using switches at an access layer, a convergence layer and a core layer, and the expansion of the network scale is limited by capacities of core switches, making it difficult to meet the needs of future service development.
In addition, in a physical network of the existing data center, an access switch and a convergence switch are directly connected using an optical fiber, and each pair of ports occupy one pair of optical fibers. If the network scale is relatively large, thousands of pairs of connecting fibers are required, which not only brings a severe challenge to physical space of an equipment room, but also brings a great difficulty in operation and maintenance, such as troubleshooting. In addition, numerous ports in the data center cause an increase of required optical modules, which are connected using multimode and multi-core optical fibers. Customization costs and connector costs of the multi-core optical fibers are very high, and cabling costs are even 3 to 4 times the costs of the optical modules.
Therefore, it is necessary to provide a new data center network, which can be beyond a limitation of core switch capacities, reduce the number of optical fibers in the data center network, save equipment room space, simplify maintenance operations on the data center network, and reduce costs of data center network construction.